in the future, christianity will probably become the greek mythology of the future.
Clocking in over two millennia and that still isn't the case. We're in a situation now where both sides have some substantial points to make, in my experience many Christians these days aren't operating on blind faith, but rather "informed faith."
History is a pendulum. Thought in Europe, for example, went through alternating periods of emphasis on emotion or reason as the ultimate. I'm a musician, and looking back through the ages, composers have somewhat alternated between "mannerism" (highly technical music designed to show off a performer's virtuosity) and holding emotionally expressive music up as the end-all. We went from the Classical period to the Romantic/Impressionist, then back to technicality in the 20th Century and the dawn of atonalism.
The masses don't know history, so they repeat this cycle (and others like it) endlessly. I don't think Christianity is seeing a trend toward its death, but our era is very much one of science and facts and technicalities (there are of course exceptions to this), and I expect we'll see a swing in the other direction eventually.